Electrical terminal means



k M i 'r. F. ARONSON ETAL 2,901,721

ELECTRICAL TERMINAL MEANS Filed Jan. 6, 1958 Aug. 25, 1959 20 I4 \w warm M m %?;Z l2 l6 2| FIG. 3 FIG. 4 FIG.5

FIG. 6 FIG. 7 FIG. 8

FIG. 9

INVENTOR.

THEODORE F. ARONSON BY FLOYD A. LYON United States Fatent ELECTRICAL TERMINAL MEANS Theodore F. Aronson, Glen Cove, and Floyd A. Lyon,

- Brookville, N.Y.

This invention relates to electrical terminal means adapted to be inserted in electrical components and particularly for resistors of the type having a resistance material deposited on the inside of hollow tubing.

The principal problem with this type resistor is the affixing of the end terminals. Heretofore, an end cap was generally clamped or otherwise fastened to each end, the cap having an extending wire for connecting purposes. The clamping of these caps is a difficult and tedious operation which must be carefully done to avoid breakage, especially since the tubing may be of a fragile nature such as glass or ceramic. With this method it is often diflicult to secure the proper electrical contact. Another prior method involved drilling holes in the tubing near the ends, which is a diflicult and expensive operation, especially with glass tubing.

The present invention solves these problems by providing an end member with spring contact fingers connected thereto, which is merely slipped into the open ends of the tubing. The spring fingers provide both electrical contact and mechanical connection. For greater mechanical strength the ends of the tubing are preferably fire-polished to form a bead or internal lip around the inside edge of the end of the tubing. If the tubing is molded, the inside lip may be an integral part thereof.

Accordingly, a principal object of the invention is to provide new and improved electrical terminal means.

Another object of the invention is to provide new and improved electrical resistor and terminal means of the type having resistance material deposited on the inside of hollow tubing.

Another object of the invention is to provide new and improved electrical resistor means of the type having resistance material deposited on the inside of hollow tubing comprising end pieces having spring finger contacts which are merely inserted in the ends of the tubing.

Another object of the invention is to provide new and improved end terminals for resistors of the type utilizing hollow tubing construction.

These and other objects of the invention will become apparent from the following specification and drawings, of which:

Figures 1 to 9 are sectional views of embodiments of the invention.

Referring to Figure 1, there is shown a sectional view of a hollow tubing 1, for instance of glass, having resistance material 2 deposited or plated on the inside surface of the tubing. The tubing is shown as having internal lips 3 and 3 at its ends.

There is provided a terminal member which comprises a plate member 5 to which is connected a plurality of spring fingers 6 and 7 which are slightly curved and tend to bend outwardly against the inside surface of the tubing. An external wire 8 is also connected to the terminal member 5 in order to make external electrical connections. The internal lip on the tubing is not absolutely necessary, but does provide a more positive mechanical connection. The internal lip may be formed Patented Aug. 25,- 1959 or four, the mechanical strength being proportional to the number of fingers. The spring fingers provide electrical contact with the resistance material on the inside of the tubing as well as the mechanical connection. The spring fingers may be made out of any electrically conducting spring material, for instance, Phosphor bronze. The end terminals are connected by merely inserting them in the ends of the tubing. If desired, they may also be cemented to the tubing.

Figures 2 to 9 show other embodiments of the invention. In Figure 2 the spring fingers 10 and 11 have a sharp bend and extend back towards the end. The ends of the spring fingers, therefore, tend to dig into the sides of the tubing to resist being pulled out.

Figure 3 shows another embodiment wherein the spring fingers are replaced by a spring member '12 which may be dish-shaped or shaped like a hemisphere and is preferably serrated or slit. The hemisphere 12 is pushed into the tubing and provides a spring-like contact against the inside walls thereof. The member 12 may comprise a plurality of fingers. The tubing 13 in Figure 3 does not require an internal lip. If desired, the end may be sealed with cement or other sealer 14.

Figure 4 shows another embodiment having long spring fingers 15 and 16 which may be adjustably placed for providing a proper resistance value. The terminal may be cemented in place after adjustment.

Figure 5 is similar to Figure 4 except the end member 20 is a threaded cylinder so that a depth gauge nut 21 may be screwed down against the ends of the tubing to fix the spacing of the contacts. The end of the tubing is preferably internally threaded.

Figure 6 shows an embodiment of the invention having a toggle arrangement. A pair of wing members 22 and 23 are pivotally mounted on a tapped center piece 24. The threaded stud 25 attached to the end member 26 is screwed into the center piece 24. The wing members are spring loaded out by spring 27 and are drawn up under the internal lip as the stud is tightened.

Figure 7 shows an embodiment wherein the resistance material 30 is deposited on the outside and continued inside around the lip to contact with the internal terminal 31, similar to terminal 12.

Figure 8 shows a capacitor comprising plates 32 and 33 which are connected to internal terminals 34 and 35 by internal connections 36 and 37. Filters and networks may be so constructed.

The internal terminals of the present invention may be used on a tubular resistor, for instance of carbon or with a solid resistor 40, Figure 9, hollowed out at the ends. The internal terminals are preferable in many uses, for instance, where there are space limitations.

The internal electrical terminals of the invention may be used in a variety of electrical components to avoid soldering caps or other type connections. They are advantageous for miniaturization and in promoting safety, as the contacts are not exposed. However, they are not limited in size but may be used for large components also.

We claim:

1. Electrical resistor means comprising a hollow tube having an internal lip projecting inwardly at its ends, resistance material deposited on the inside surface of said hollow tube, and terminal means comprising a member having at least two spring means, said spring means being adapted to fit behind said internal lip in a positive manner to provide electrical and mechanical contact between said member and said tube.

2. Electrical resistor means comprising a hollow tube having an internal lip projecting inwardly at its ends, re-

sistance material deposited on the inside surface of said 5 References Cited in the file of this patent v UNITED STATES PATENTS 1,031,787 Hallock July 9, 1912 15 4 Lofgren May 20, Church Aug. 18, Schoeppler Nov. 23, Vansickle July 30, Pende-r et a1 Dec. 10, Van Lovn Mar. 22, Dorst Aug. 8,

FOREIGN PATENTS Great Britain Sept. 13, France May 13, Germany Jan. 12, 

